Pyro

sorry no dimensions, however....... I think it was easier just to make my own mount using 1/4" thick x 2 inch wide plate steel. Just install the transmission were you want it then build a mount around the trans tunnel and trans mount. really easy. The mount I made was straight across at the mount then had a little 1.5" upward offset for exhaust clearance then angled up on the ends to match the trans tunnel. The mounting bolts (2 on each side) are in the vertical section of the trans tunnel above the transmission mount. It fits perfectly since I tack-welded everything in place under the car. And is about 1/3 the size of the JTR mount.

there two bolts to adjust the distributor. the 10mm right there on top and another under the distributor plate (8mm) that hold the distributor to the plate. It sounds like you need to adjust the plate screw which you can't see very well from the top. furthermore. balancers will slip over the years. You need to check for true TDC with a piston stop to check if the balancer has slipped or not.

Use the 240mm. it is not the hp but the torque that is the problem. A mild 240mm clutch will typically hold more torque than a race 225mm clutch. go to nipponpower.com then go to the clutch section, check out the SPEC clutches. a stage 1 240mm clutch holds more torque than a stage 3 225mm clutch. and the 240mm stage 1 or 2 drives like a stock clutch and the 225 stage 3 is a pain to drive on the street.

check out this site. http://www.geocities.com/z_design_studio/ early 5spd gears: 3.321, 2.077, 1.308, 1, 0.864 later 5spd gears: 3.062, 1.858, 1.308, 1, 0.745 turbo T5 gears: 3.500, 2.144, 1.375, 1, 0.78 max speed with 215/60/15 tires and 6,000 rpm early 5 spd w/ 3.54= 38, 61, 97, 127, 147 later 5 spd w/ 3.90= 38, 62, 88, 115, 155 turbo T5 with 3.54 = 36, 59, 92, 127, 163 later 5 spd w/3.54 = 41, 68, 97, 127, 170

yes, turbo cars came stock with 3.54, but the transmission gears in the T5 are set up for 3.54 gears. T5's have higher numeric gears in 1st and 2nd as compared to late model NA 5 spd. so really, the later model NA 5 spd with a 3.90 gear has about the same ratios as a T5 turbo trans with a 3.54 gear. And that is about the same as an early model NA 5 spd with a 3.54. Therefore the T5 and the early model NA 5 spd are wide ratio transmissions. when comparing rear end gears, the trans gears must also be considered. I say, stay with the 3.90 gear if you have a later model NA 5 spd. Gears are good for acceleration (turbo or not). A 3.54 gear with a later model 5 spd will slow you down, but will lower rpms 10% as compared to the 3.90. The question is, what year NA 5 spd do you have? if you have an early 5 spd (77 to 78) then a 3.54 gear will be just about where the stock turbo set up is. If you have a later model 5 spd (81 to 83) then the 3.90 gear would work nicely.

those are high numbers for a turbo engine. if the engine has not run for a while then a little rust or crap could have got stuck on the #1 and #6 valves, which will lower the cranking pressure. I would run it to see how it does. Look at the back sides of the valves with the manifolds off, if they all look the clean, then run it as is.

yes, much better to have a return system. keeps the gas cool and pressure constant. However, if the pump isn't designed to run a return then don't run one. The pump needs to put out more pressure that the fuel system needs then the return line lets the excess go back to the tank to regulate the pressure. if a pump can't make more pressure than required then no return should be used. and about the stock sbc pump.... some mechanical pumps for sbc require a return and others don't. typically earlier sbc pump don't use return a line but later model pumps do require them to bleed off the excess pressure. If a 75 mech pump is used without a return , it will over power the needle and seat of a carb. Back to the 240. I have run my 240 with and without the return line line. I really didn't notice much difference. However, I was only 20, and I didn't notice as much back then. I would use the return line if you are using the stock pump. Just make a new clean cut on the return metal line and run a longer rubber gas line to the meal line. You don't need barbs, as the pressure is very low, just make sure to match the ID of the rubber hose to the OD of the metal line as close a possible.

It is good to know what the lift and duration are. However on a L series datsun engine, the lift at the valve depends on the location of the wipe pattern, as this effects the ratio of the rocker arm. The amount of lash also effects the lift by a small amount. Furthermore, 280 degree cam compared to a 276 degrees cam will not be noticeable.

Even with an acceptable wipe pattern (at the edge of the pivot ball side), there will be a lot of clearance between the lash pad and the rocker arm even after the valve are set at a tight 0.008". The extra clearance at the lash pad makes the valve train sound like a diesel. If you want a quiet valve train then you need to set the wipe pattern closer to the valve side, and that takes thick lash pads and after market retainers. 0.160" max spec is in the "how to modify Datsun L series engines". stock lash pad retainer wells are shallow compared to aftermarket retainer wells.

you are going to need thicker lash pad with that cam! I would guess 0.200". courtesy nissan sells them for 3.00/each. However, 0.160" is the thickest you can put in stock retainers. High performance retainer's typically had deeper retainer holes for thicker lash pads. If the lash pad is too thin the valve train will sound like a diesel and may eat the cam lobes if the wipe pattern goes off the rocker arm pad.

the reason that overlap doesn't effect cylinder pressure is the 4 stroke engine isn't trying to build cylinder pressure during that part of the cycle (over lap period). It is during the compression stroke that cylinder pressure is made and the exhaust valve is long closed by then. However, the intake valve can be still open during the compression stroke, even as the piston is rising in the bore. This is especially true in long duration cams. so the amount of stroke the piston actual gets to compressed is reduce if the intake valve is still open. overlap does effect the idle quality (vacuum) and does help the intake fill the cylinders by way of exhaust scavaging.

You are on the right track. You are talking about dynamic compression ratio (DCR) which considers the intake closing point along with the static compression ratio (SCR) to figure out cylinder pressure. Some people will say it is the valve overlap that bleeds off cylinder pressure but it isn't. The intake closing point on the compression stroke is what controls the amount of cylinder pressure bleed off. Different engine designs have difference amount of cylinder pressure tolerance so there isn't any hard rules for static compression and cam duration tolerance with pump gas. However for a L28, a 284 degree cam runs well with 10:1 cr. And should run without any special tuning up to 10.5:1 cr with 91 to 93 octane.

of course adding boost increases cylinder pressure. that is a given. but, delaying the intake valve closing point with a longer duration cam will lower cylinder pressure, with or without boost. yes that is right, the pressure from the pistons makes an order of magnitude (10x) more pressure than the boost from the turbo.

mine does that a little also. I plan to install an injector blower motor and a momentary switch for the fuel pump. Not sure how I'm going to control the blower yet, but will make some sort of timer that activates after the ignition is shut off. (rc circuit, ic timer, transistor, and relay) and will plan to run the fuel pump for 10 or 20 seconds before start up with the momentary switch. I'll most likely try the momentary switch first because that will be the easiest.

no, compression doesn't begin until the intake valve closes. until then, air is pushed back into the intake. yes, boost helps fill the cylinder, but doesn't make nearly the cylinder pressure the piston does when compressing the charge.

try a bigger cam. longer duration on the intake valve will lower cylinder pressure. try a NA cam. has 8 more degrees on the intake. or try a msa stage 1 turbo cam which has 20 more degrees.

here is a few more

I moved the afm up front. works great. also, reclocked the turbo and ran output from turbo under the engine to allow the use of the stock fan and shroud.

I prefer running heavy springs in the rear and light to stock springs up front. This is a good set up for drag racing and also a good setup for a car that understeers (plows) like an old Z tends to do.

make sure the 2 little 8mm screws are out that go into the timing chain. wack the side of the head with a rubber pallet. It should lift off easily. you are going to have problems getting the broken bolts out. may end up pulling the block and having a machine shop do it.

have you read post #6???

just get an ac shop to make some custom hoses to connect the new compressor to the old lines. A friend of mine recently did that. cost around 150.00.

it will fit if you use a drop base filter housing and if you used the 1/2 inch body spacers.

cooling not important??? the mounting position makes a difference, especially in the south. I had read a few general "engine swap books" and air space around the transmission is a major concern. Plus I have done a few V8 conversion on z's and have had cooling issues with automatic trans plugging the hot air escape path. however, if the z is not a true daily driver then the cooling will not be an issue. What I mean by daily driver is a V8 z that has AC and can sit in a traffic jam on a 100 degree day without over heating (like a new car).

there are two types of Z oil pans. rear sump and center sump. As long as the matching pickup tube for the oil pump is used then you can use any pan. That is, use a rear sump pick up tube with a rear sump pan, or use a center sump pickup with a center sump pan. A turbo is a rear sump pan. A 280z uses a center sump pan furthermore, you can use any style pan for a turbo as long as you install the turbo drain line in the same position as the stock turbo pan.